AKE – an electronic dead end

The AKE electronic switching system was one of Ericsson's most important switch families, despite its limited success in the market. The reason was that it provided the foundation for Ericsson's success with the AXE system.

The designation AKE denoted a family of automatic code selector-based electronic switches (Swedish: Automatiska Kodväljarbaserade Elektronikväxlar) and was Ericsson's first commercial attempt to develop a computerized telephone switch. The company's development of electronic switches began in 1954, when the experimental prototype EMAX was presented. In 1956, joint research and development work was started with Televerket, the Swedish PTT, and an Electronics Council was established to coordinate the two companies.

Ericsson planned to continue design work on a commercial EMAX2 switch but postponed the project when its US subsidiary North Electric in 1960 received an order from the US Air Force for a 412-L switch with several hundred lines. This was Ericsson's first practical electronic switch and was delivered in 1963. When it was later also sold to the Swedish Air Force, it became the first electronic telephone station outside the US. At the same time, the company had started development work on designing the AKE switch, which would be the first stage in a larger, more sophisticated switching family for commercial telephone stations.

The first AKE project was started in 1962 for the development of the AKE 12 switch, which was an electronic and computer-controlled telephone switch for Televerkets local station in Tumba in the south of Stockholm. The AKE was based on electronically controlled electromagnetic code selectors that were a refinement of the crossbar switch that Ericsson had developed in the 1950s.

In other respects, the design was similar to the first American computer-controlled switches and used an analog system with stored instructions. The project was included in part in the joint development work with Televerket in that the public operator was conducting a largely similar development project. It was difficult, however, for the two parties to cooperate and not to view each other as competitors. The solution was that the two companies traded markets so that Televerket would develop a small urban station, while Ericsson would focus on a large local station.

At the beginning of 1967, practical testing of the AKE 12 station began by connecting a few subscribers. This resulted in major problems, however, since the large computer programs used to control the station were not completely bug-free. The occurrence of program errors had been seriously underestimated, and no other method of identifying the errors could be found than putting the switch into practical operation. The result was an extensive test that was extremely expensive.

Around 1964, Ericsson realized that there was a relatively large market for automatic switching stations for transit traffic with a capacity of about 20,000 calls. It was therefore decided to focus development of computer-controlled switching stations on this segment. The idea was that the stations would be able to use the same hardware in all countries and custom software in each individual country.

In 1966, Ericsson decided to establish a second development program and to design a more extensive system for multi-processor control. This system was called AKE 13. It was to be primarily a switch for large transit station that connected inter-city and international telephone calls with lower traffic volumes than local stations that switched calls directly to subscribers. The market for this type of switch, however, was relatively limited.

Ericsson succeeded in winning an AKE order in 1968 and 1969 for more than 2,000 lines for a transit station in Rotterdam. SPC was used for automation of the switch, which with its eight processors was the world's first multi-processor switching system.

The Rotterdam station was inaugurated in 1971, and in 1971, a second and larger AKE station was opened in Copenhagen. This was followed by additional international orders. By 1981, Ericsson had delivered 37 AKE switches to ten different countries. North Electric also manufactured a version of the AKE 13 switch called the ETS34 for the American market. The AKE 13 was a relatively expensive and slow switch, however, and by the late 1960s, the AKE was no longer economical for local station with more than 10,000 subscribers. The solution for the future was to be AXE.

Author: Mats Fridlund

THE NETHERLANDS, 1971, AKE TELEPHONE STATION

Inauguration. Standing: from the left Björn Lundvall president of Ericsson, Marcus Wallenberg jr chairman of Ericsson.